Carbon II Oxide

Carbon(II) oxide is a strong poison Perform the experiments only in a fume cupboard, lower the glass window  

Carbon(II) oxide (carbon monoxide) is prepared under laboratory conditions from formic or oxalic acid (prepare it only in one of these ways). 

Preparation of Carbon(II) Oxide from Formic Acid and Studying Its Properties. 1. Assemble an apparatus as shown in Fig. 104. Pour 20 ml of a concentrated sulphuric acid solution into the 100-ml Wurtz flask, 15 ml of formic acid into the dropping funnel, a small amount of vaseline oil (a bubble counter) into the first wash bottle, and leave the second wash bottle empty. Put about 0.1 g of copper(II) oxide in the middle of a tube made from refractory glass, preferably with a widened part at its middle. Pour water into the crystallizer. 

Carefully heat the flask with the sulphuric acid up to 60 °C and add the formic acid dropwise to it. Collect the evolving gas over the water in a small jar and test it with a burning splinter. What do you observe  

Having completely displaced the air from the apparatus (how can this be proved ), heat the part of the tube where the copper oxide is with the flame of a burner in a stream of carbon(II) oxide. How 

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Fig. 104. Apparatus for preparing carbon(II) oxide and studying its properties...

Remove the bath with water, remove the rubber tube with a bent glass tip from the end of the apparatus, and pass the carbon(II) oxide through ammonia solutions of silver nitrate and copper(I) chloride poured into test tubes. What happens Does the carbon(II) oxide exhibit the same properties in these reactions How can one prove that carbon(II) oxide will evolve when the formed complex compound of copper(I) is heated ... 

After completing the experiments, cool the apparatus in a stream of carbon(II) oxide. Disconnect the refractory tube, extract the preparation from it and hand it in to your instructor. 

Preparation of Carbon(II) Oxide from Oxalic Acid and Studying Its Properties. Assemble an apparatus as shown in Fig. 104, sub-... 

Study the properties of the carbon(II) oxide as indicated above. CARBIDES... 

Carbon(II) oxide (always known as carbon monoxide)... 

All Group IV elements form both a monoxide, MO, and a dioxide, MO2. The stability of the monoxide increases with atomic weight of the Group IV elements from silicon to lead, and lead(II) oxide, PbO, is the most stable oxide of lead. The monoxide becomes more basic as the atomic mass of the Group IV elements increases, but no oxide in this Group is truly basic and even lead(II) oxide is amphoteric. Carbon monoxide has unusual properties and emphasises the different properties of the group head element and its compounds. 

Lead(II) oxide is easily reduced to the metal when heated with a reducing agent such as hydrogen, carbon or carbon monoxide, for example ... 

Dibromine monoxide, BtjO, is prepared, similar to the corresponding dichlorine compound, by the action of a solution of bromine in carbon tetrachloride on yellow mercury(II) oxide ... 

On heating, the basic carbonate readily yields the black copper(II) oxide. 

Zinc(II) oxide, ZnO, is prepared by heating the hydroxide ZnlOH) or the carbonate ZnCOj. It is a white solid, insoluble in water, but readily soluble in acids to give a solution containing the zincfll) cation, and in alkalis to give a hydroxozincate(II) anion ... 

Nantokite, see Copper(I) chloride Natron, see Sodium carbonate Naumannite, see Silver selenide Neutral verdigris, see Copper(H) acetate Nitre (niter), see Potassium nitrate Nitric oxide, see Nitrogen(II) oxide Nitrobarite, see Barium nitrate Nitromagnesite, see Magnesium nitrate 6-water Nitroprusside, see Sodium pentacyanonitrosylfer-rate(II) 2-water... 

Nickel Carbonyl The extremely toxic gas nickel carbonyl can be detected at 0.01 ppb by measuring its chemiluminescent reaction with ozone in the presence of carbon monoxide. The reaction produces excited nickel(II) oxide by a chain process which generates many photons from each pollutant molecule to permit high sensitivity (315). 

Manganese Nitrate. Manganese nitrate [10377-66-9] is prepared from manganese(II) oxide or carbonate using dilute nitric acid, or from Mn02 and amixture of nitrous and nitric acids. Mn(N02)2 exists as the anhydrous salt [10377-66-9]-, the monohydrate [3228-81-9]-, ttihydrate [55802-19-2],... 

Tantalum(II) oxide [12035-90-4] TaO, is the only other oxide the existence of which has been confirmed. It can be prepared from Ta20 by reduction with carbon at 1900°C or with H2 at 1100°C. 

Methanol Synthesis. Methanol has been manufactured on an industrial scale by the cataly2ed reaction of carbon monoxide and hydrogen since 1924. The high pressure processes, which utili2e 2inc oxide—chromium oxide catalysts, are operated above 20 MPa (200 atm) and temperatures of 300—400°C. The catalyst contains approximately 72 wt % 2inc oxide, 22 wt % chromium (II) oxide, 1 wt % carbon, and 0.1 wt % chromium (VI) the balance is materials lost on heating. 

Cobalt metal is significantly less reactive than iron and exhibits limited reactivity with molecular oxygen in air at room temperature. Upon heating, the black, mixed valence cobalt oxide [1308-06-17, Co O, forms at temperatures above 900°C the oHve green simple cobalt(II) oxide [1307-96-6] CoO, is obtained. Cobalt metal reacts with carbon dioxide at temperatures greater than 700°C to give cobalt(II) oxide and carbon monoxide. 

Copper Oxides. Coppet(I) oxide [1317-39-17 is a cubic or octahedral naturally occurring mineral known as cuprite [1308-76-5]. It is ted or reddish brown in color. Commercially prepared coppet(I) oxides vary in color from yellow to orange to ted to purple as particle size increases. Usually coppet(I) oxide is prepared by pytometaHutgical methods. It is prepared by heating copper powder in air above 1030°C or by blending coppet(II) oxide with carbon and heating to 750°C in an inert atmosphere. A particularly air-stable coppet(I) oxide is produced when a stoichiometric blend of coppet(II) oxide and copper powder ate heated to 800—900°C in the absence of oxygen. Lower temperatures can be used if ammonia is added to the gas stream (27-29). 

Coppet(II) oxide [1317-38-0] CuO, is found in nature as the black triclinic tenorite [1317-92-6] or the cubic or tetrahedral paramelaconite [71276-37 ]. Commercially available copper(II) oxide is generally black and dense although a brown material of low bulk density can be prepared by decomposition of the carbonate or hydroxide at around 300°C, or by the hydrolysis of hot copper salt solutions with sodium hydroxide. The black product of commerce is most often prepared by evaporation of Cu(NH2)4C02 solutions (35) or by precipitation of copper(II) oxide from hot ammonia solutions by addition of sodium hydroxide. An extremely fine (10—20 nm) copper(II) oxide has been prepared for use as a precursor in superconductors (36). 

Copper(II) oxide is less often prepared by pyrometaHurgical means. Copper metal heated in air to 800°C produces the copper(II) oxide. Decomposition of nitrates, carbonates, and hydroxides at various temperatures also occurs. 

Copper(II) oxide is insoluble in water, but readily dissolves in mineral acid or in hot formic or acetic acids. CuO slowly dissolves in ammonia solution, but alkaline ammonium carbonate solubilizes it quickly. 

At least two pathways have been proposed for the Nenitzescu reaction. The mechanism outlined below is generally accepted." Illustrated here is the indolization of the 1,4-benzoquinone (4) with ethyl 3-aminocrotonate (5). The mechanism consists of four stages (I) Michael addition of the carbon terminal of the enamine 5 to quinone 4 (II) Oxidation of the resulting hydroquinone 10 to the quinone 11 either by the starting quinone 4 or the quinonimmonium intermediate 13, which is generated at a later stage (HI) Cyclization of the quinone adduct 11, if in the cw-configuration, to the carbinolamine 12 or quinonimmonium intermediate 13 (IV) Reduction of the intermediates 12 or 13 to the 5-hydroxyindole 6 by the initial hydroquinone adduct 7 (or 8, 9,10). 

Cupri-. cupric, copper(II). -azetst, n. cupric acetate, copper(II) acetate, -carbonat, n. cupric carbonate, copper(II) carbonate, -chlorid, n. cupric chloride, copper(II) chloride. -hydroxyd, n. cupric hydroxide, cop-per(II) hydroxide. -ion, n. cupric ion, copper(II) ion. -ozalat, n. cupric oxalate, copper(II) oxalate, -oxyd, n. cupric oxide, copper(II) oxide. -salz, n. cupric salt, copper(II) salt, -suifat, n. cupric sulfate. copper(II) sulfate, -sulfid, n. cupric sulfide, copper(II) sulfide, -verbihdung, /. cupric compound, copper(II) compound, -wein-saure, /. cupritartaric acid. 

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